A Reconfigurable Intelligent Surface for Broadband Achromatic Beam Deflection

Metasurfaces have excellent capabilities that can arbitrarily control the phase.,amplitude., and polarization of electromagnetic waves. However, traditional metasurfaces have inherent dispersion and lack of tunability, which seriously restrict their development and application. This paper proposes a reconfigurable intelligent surface (RIS) to effectively manipulate the wavefront in a broadband and achromatic manner. Because the dynamically tunable components can control the dispersion and the direction of the beam deflection, the broadband effect and flexible tunability of the metasurface can be achieved simultaneously. The relative bandwidth of the dynamic achromatic RIS can reach 14%, and a beam deflection range of 25° is achieved. The proposed approach possibly promotes the progress of RIS-aided wireless communications and RIS-based information transmission.